Drive support display apparatus

ABSTRACT

An object of the invention is to provide a driving assistance display apparatus that enables the driver to check safety of the rear of the vehicle and grasp the limited area around the vehicle in the final stage of parking without switching screens.  
     A screen to display an image of the rear of a vehicle shot by a vehicle-mounted camera is divided into a main screen ( 10 ) and a sub-screen ( 11 ). A wide area image in the rear of the vehicle is displayed on the main screen together with guide lines ( 15, 16 ) superimposed on the main screen ( 10 ). An image of the rear of the vehicle from the image is viewpoint-converted to an image from a virtual viewpoint located above the vehicle. The resulting image is displayed on the sub-screen ( 11 ) together with guide lines ( 15   a,    16   a ), also view point thereof is converted, superimposed on the sub-screen ( 11 ). Preferably, the center axis of the main screen ( 10 ) coincides with the center axis of the sub-screen ( 11 ) and the sub-screen  11  is arranged below the main screen ( 10 ).

TECHNICAL FIELD

[0001] The present invention relates to driving assistance displayapparatus that processes an image in a rear direction of a vehicleacquired by a vehicle-mounted camera and present the image to thedriver.

BACKGROUND ART

[0002] Driving assistance display apparatus has been in widespread usethat provides the driver with the view at the rear of a vehicle withoutthe driver looking into a rearview mirror, by mounting a vehicle-mountedcamera, e.g. on the rear trunk of a vehicle, in a rear direction andpresenting the image acquired from the vehicle-mounted camera to thedriver. Some of such driving assistance display apparatus converts areal image from a vehicle-mounted camera to an image from a virtualviewpoint and display the image on a monitor. Such driving assistancedisplay apparatus is used to assist safety in backing a vehicle andparking.

[0003]FIG. 3 shows a block diagram of a general driving assistancedisplay apparatus. The driving assistance display apparatus includes acamera 2 mounted on a vehicle 1, image synthesis/conversion device 3 forprocessing an image shot by the camera 2, and a monitor 4 for displayingan image acquired after the image synthesis/conversion processing.

[0004] The camera 2 is mounted to shoot the rear of the vehicle 1. Animage acquired by the camera 2 has undergone processing to remove lensdistortion by the image synthesis/conversion device 3 and is convertedto an image as if shot from an arbitrary virtual viewpoint and displayedon the monitor 4.

[0005]FIG. 4 is an input image to the camera 2. FIG. 5 shows an imageacquired by setting a virtual viewpoint over the vehicle 1 andconverting a real image to an image of the rear of the vehicle from thevirtual viewpoint. An image shown in FIG. 4 is an image shot by thecamera 2 as a wide angle camera without conversion. Thus the rear bumperimage 5 that is actually a straight line is distorted. A guide line 6 issuperimposed at the same time. The guide line 6 includes a vehiclepassing guide line 7 indicating the vehicle width (body line) and adistance guide lines 8 indicating the distance from the rear of thevehicle on the road surface.

[0006]FIG. 5 shows an image acquired by viewpoint-converting the imagein FIG. 4 to be seen from a virtual viewpoint. A rear bumper image isconverted to a straight line image 5 a. A vehicle passing guide line 7 aand a distance guide lines 8 a of a guide line 6 a are also displayed asstraight line images on the monitor 4. The driver watches the image inFIG. 5 on the monitor as he/she parks the vehicle. While a singlevehicle-mounted camera is used in the example of FIG. 3, it is possibleto synthesize images from a plurality of cameras and display theresulting image on the monitor.

[0007] In the conventional driving assistance display apparatus, thesame screen is used to implement the procedures including safety checkand parking. An image with a wide field of view of the rear of a vehicleis appropriate for safety check, while an image from a virtual viewpointin the close proximity of a vehicle is advantageous for parkingassistance. In this way, suitable images differ with purposes.

[0008] In the case of parking assistance also, an image of a wide fieldof view is required in order to grasp the global situation around avehicle thus guiding the vehicle to its parking space in the initialstage of parking. In the final stage of parking, only a limited areaaround the vehicle must be grasped for alignment. As such, the optimumimage depends on the stage of parking although a same operationprocedure.

[0009] Representing an image of a wide field of view to the driver whenit is necessary to grasp only a limited area around the vehicle adds tothe distortion of a three-dimensional object caused by viewpointconversion. This is impractical because it leads to a sense ofincongruity in the parking procedure or failure to recognize thethree-dimensional object.

[0010] To offset this, for example at least in the conventional parkingprocedure, an image of a wide field of view required in the initialstage of parking is switched to an image of a limited area around thevehicle as necessary. However, switching of images in the sequence ofparking operation obliges the driver to understand the correspondencebetween images before and after the switching, which is not veryfavorable.

[0011] For resolving the above problem, the invention aims at providingdriving assistance display apparatus that enables the driver to checksafety of the rear of the vehicle and grasp the limited area around thevehicle in the final stage of parking without switching screens.

DISCLOSURE OF THE INVENTION

[0012] Driving assistance display apparatus according to the inventionis intended to display an image of the rear of a vehicle shot byshooting means in the main screen area and sub-screen area as splitimages, characterized in that the driving assistance display apparatuscomprises display control means for displaying a wide area image of therear of the vehicle in the main screen and displaying aviewpoint-converted image of the rear of the vehicle in the sub-screen.

[0013] With this configuration, it is possible to display two types ofimages that suit separate purposes in the main screen area andsub-screen area in the same screen. The driver can simultaneously checkthe two images that suit two types of purposes on the same screen. Thiseliminates the need for switching screens and provides seamlessassistance of driving procedure.

[0014] Preferably, the display control means superimposes guide lines towhich respective relation corresponds on the main screen area and thesub-screen area and causes the center axis of the main screen area tocoincide with the center axis of the sub-screen area, as well asarranges the sub-screen area below the main screen area.

[0015] With this configuration, the same guide line is displayed both inthe main screen area and sub-screen area. This allows the driver tointuitively grasp the relative relation between the main screen area andsub-screen area. The travel direction of the vehicle coincides with thetravel direction of field of view between the main screen and thesub-screen. This avoids irritating interruption of shift in line ofsight in the screen during driving, thus providing a display screen thatpromises easy driving.

[0016] Preferably, the display control means arranges the sub-screenarea in an upper right hand corner or an upper left hand corner of themain screen area. As the upper right hand corner and the upper left handcorner of the main screen area are prone to be distorted, the sub-screenis arranged in place of a distorted image. Therefore, the driver doesnot sense incongruity by the distorted image. As a result, the screen iseffectively used.

BRIEF DESCRIPTION OF THE DRAWING

[0017]FIG. 1 is a block diagram of a display screen according to thefirst embodiment of the invention;

[0018]FIG. 2 is a block diagram of a display screen according to thefirst embodiment of the invention;

[0019]FIG. 3 is a general block diagram of a driving assistance displayapparatus;

[0020]FIG. 4 explains a conventional display screen; and

[0021]FIG. 5 explains a conventional display screen acquired afterviewpoint conversion.

[0022] Numeral in the drawings, 1 is a vehicle, 2 is a vehicle-mountedcamera, 3 is an image synthesis/conversion apparatus (image processingmeans), 4 is a monitor, 10 is a main screen, 11 is a sub-screen, 13, 13a are rear bumper image, 14 is an image of another vehicle, 15, 15 a arevehicle passing guide line image, and 16, 16 a are a distance guide lineimage.

BEST MODE FOR CARRYING OUT THE INVENTION

[0023] Embodiments of the invention will be described referring todrawings.

[0024] (Embodiment 1)

[0025] Configuration of driving assistance display apparatus accordingto the first embodiment of the invention is the same as that in FIG. 3.The driving assistance display apparatus according to the firstembodiment includes a camera 2 mounted on a vehicle 1, an imagesynthesis/conversion device (display control unit) 3 for processing animage shot by the camera 2, and a monitor 4 for displaying an imageacquired after the image synthesis/conversion processing.

[0026] The camera 2 is mounted to shoot the rear of the vehicle 1. Animage acquired by the camera 2 has undergone processing to remove lensdistortion by the image synthesis/conversion device 3 and is convertedto an image as if shot from an arbitrary virtual viewpoint and displayedon the monitor 4.

[0027]FIG. 1 shows the configuration of a monitor screen displayaccording to the first embodiment of the invention. Imagesynthesis/conversion device 3 of the embodiment displays an image of awide range in the rear of the vehicle 1 and displays an image acquiredby converting an image of the rear of the neighborhood of the vehicle 1to an image from a virtual viewpoint above the vehicle. A main screen 10and a sub-screen 11 are displayed as a single screen on the monitor 4.The driver can simultaneously watch both screens 10, 11.

[0028] On the main screen 10, an image acquired by converting a wideangle image shot by the camera 2 is displayed, and the wide angle imageshot by the camera 2 is converted to be obliquely viewed from above tosee the rear bumper 13 and a wide range image of the rear of the vehicle1 including the an image of another vehicle 14 around the vehicle, andis converted so that a straight line in the real space is displayed as astraight line. At the same time, guidelines composed of a vehiclepassing guide line image 15 and a distance guide line image 16 similarto the guide line 6 explained in FIGS. 4 and 5 are superimposed.

[0029] On the sub-screen 11 is displayed an image of the area near therear of the vehicle 1 where the vehicle passing guide line image 15 andthe distance guide line image 16 are displayed. The image in thesub-screen 11 has undergone the conversion whereby an image of the areanear the rear of the vehicle 1 is cut away and converted to a plan imagefrom a virtual viewpoint just above the vehicle. Thus, the rear bumperimage and guide line image are images 13 a, 15 a, 16 a acquired byconverting the images 13, 15, 16 for use in the sub-screen 11.

[0030] The main screen 10 is preferable for safety check of the areaaround the vehicle and vehicle guidance in the initial stage of parking.The sub-screen 11 is preferable mainly for use in vehicle positionadjustment in the final stage of parking. With such a screenconfiguration, the driver checks the safety around the vehicle andguides the vehicle to its parking space while watching the main screen10 in the initial stage of parking.

[0031] The guide lines 15, 15 a, 16, 16 a are used in common by the mainscreen 10 and the sub-screen 11. This allows the driver to recognize ina single screen the relation between the display of the guide lines 15,15 a, 16, 16 a and mark images on the road surface such as a parkingborder line (not shown). The driver easily understands whether theon-road mark image has entered the sub-screen 11 as the vehicle 1 beingbacked approaches the on-road mark.

[0032] The sub-screen 11 displays an image from a virtual viewpoint. Itis thus possible to correctly grasp the relative relation between thevehicle 1 and a on-road mark by using the sub-screen 11. Thus, in thefinal stage of parking when a on-road mark is displayed in thesub-screen 11, the driver simply shifts the line of sight from the mainscreen 10 to the sub-screen 11 to minutely adjust the turning angle ofthe vehicle 1 with respect to the parking space and the distance to amark in the rear, based on the image display in the sub-screen 11.

[0033] In this way, this embodiment shows two types of images that suitrespective purposes in a single screen at the same time. The driver hasonly to shift the line of sight to select an image that suits thecurrent purpose thus seamlessly performing a parking sequence withoutinterruption.

[0034] In this embodiment, the sub-screen is in the upper right cornerof the main screen 10. This is to efficiently use the screen. An imagedisplayed in the main screen 10 has undergone viewpoint conversion. Thusa farther image, that is, an image in the innermost area in the upperleft or upper right corner, results in a more distorted image. Such animage may give the driver a sense of incongruity. So, in thisembodiment, the sub-screen 10 is provided in the upper right cornerinstead of an image in the main screen 10.

[0035] (Embodiment 2)

[0036]FIG. 2 shows the configuration of a monitor screen displayaccording to the second embodiment of the invention. In the drivingassistance display apparatus according to this embodiment, thesub-screen 11 is provides elsewhere than the first embodiment. In thisembodiment, the center axes of the main screen 10 and the sub-screen 11coincide with the center axis of the backing direction of the vehicle 1and the sub-screen 11 is arranged below the main screen 10.

[0037] In case the vehicle is backed in parking procedure, an image inthe main screen 10 shifts from the upper area of the screen to theposition of the bumper image 13 at the bottom of the screen. Thus, theline of sight of the driver parking the vehicle while watching the imagein the main screen 10 mainly shifts in vertical direction. In case thedriver watches the image in the sub-screen 11 also, the line of sight ofthe driver shifts in vertical direction.

[0038] Screen configuration of this embodiment considers such shift ofthe line of sight of the driver. By causing the center axis of the mainscreen 1 to coincide with the center axis of the sub-screen 11 andproviding a single direction of line of sight in both screens, thisembodiment reduces the load on the driver. The driver can drive thevehicle while watching the screens 10, 11 or seamlessly shift the lineof sight from the main screen 10 to the sub-screen 11 or from thesub-screen 11 to the main screen 10, without experiencing aninterruption of a shift in line of sight.

[0039] In case the relation between the main screen 10 and thesub-screen 11 is two-dimensionally interrupted, an unskilled driver mayfail to understand the correspondence between the main screen 10 to thesub-screen 11 at a glance. By using the configuration of this embodimentwhere the driver can watch the main screen 10 and the sub-screen 11sequentially on a one-dimensional basis, the driver does not feel stressin shifting the line of sight and is able to intuitively grasp thecorrespondence between both screens.

[0040] The invention was explained in detail referring to specificembodiments. It is clear for a person skilled in the art that variousalternation and modification are made without deviating from spirit andrange of the invention.

[0041] This application is based on Japanese Patent Application(P2001-300283) filed on Sep. 28, 2001. The contents of the applicationare incorporated as references.

INDUSTRIAL APPLICABILITY

[0042] According to the invention, it is possible to use the main screenand the sub-screen in a single screen depending on the specific purpose.It is thus possible to check an image that matches the purpose in asingle screen thus preferably assisting driving procedure.

[0043] The invention causes the center axis of the main screen tocoincide with the center axis of the sub-screen to allow easyunderstanding of the correspondence between the travel direction of thevehicle and the direction of shift in the line of sight between the mainscreen and the sub-screen. This provides a display screen wherebydriving is made easy.

1. A driving assistance display apparatus comprising for displaying animage of the rear of a vehicle shot by an imaging device, said drivingassistance display apparatus comprising: a display control unit fordisplaying a wide area image of the rear of the vehicle in a main screenarea and displaying a viewpoint-converted image of the rear of thevehicle in a sub-screen area, wherein the main screen area and thesub-screen area is displayed on a same display screen.
 2. The drivingassistance display apparatus according to claim 1, wherein said displaycontrol unit superimposes a guide line to which respective relationcorresponds on said main screen area and said sub-screen area.
 3. Thedriving assistance display apparatus according to claim 1 or claim 2,wherein said display control unit allows the center axis of said mainscreen area to coincide with the center axis of said sub-screen area. 4.The driving assistance display apparatus according to any one of claims1 to 3, wherein said display control unit arranges the sub-screen areabelow the main screen area.
 5. The driving assistance display apparatusaccording to any one of claims 1 to 3, wherein the display control meansarranges the sub-screen area in an upper right hand corner or an upperleft hand corner of the main screen area.